The objective of the Animal and Molecular Biology core is to serve the participating investigators of this PPG by 1) maintenance and breeding of transgenic and knockout (KO) mouse colonies and their genotyping, 2) cryopreservation of embryos and sperms from these mouse lines, and 3) performing in situ hybridization for detection of cell-specific mRNA localization for gene expression studies. The participating investigators already possess more than 30 lines of transgenic and KO mice on their own capacity. Many of these lines have already shown to be useful as models for cancer research. Therefore, the initial goal of this core will be to centralize and maintain these lines. However, maintenance of mouse colonies needs constant supervision and it is a labor-intensive endeavor. The establishment of this core will reduce the workloads of individual investigators and will be extremely cost-effective. Following the initial establishment, however, additional lines will be added for the purpose of the program. Thus, centralizing animal husbandry in this core and having dedicated personnel to perform routine duties will improve the quality and efficiency of this program. Another important role of this core will be to preserve these transgenic/KO lines by cryopreservation of embryos and sperms simply to avoid any inadvertent loss of lines and for future use by scientists. Additionally, all projects under this PPG also involve studies in relation to the cell-specific mRNA analysis for gene expression in tissues/cells. For the last 12 years, we have been involved to develop and adapt a very sensitive technique of in situ hybridization for gene expression studies for virtually all kinds of frozen tissue sections. Using this technique, we have been able to detect extremely low expression of mRNAs on tissues that are comprised of heterogeneous cell types. Our primary goals are to: 1) perform routine husbandry of transgenic and KO mice used in this program; 2) carry out genotyping of transgenic mice and database management; 3) perform cross-breeding of genetically defined mouse strains including creation of double or multiple gene knock-out mice; 4) provide KO mice or tissues to investigators; 5) perform cryopreservation of embryos and sperms from KO mice; 6) develop and/or maintain various cDNAs for their use as molecular probes in hybridization studies; 7) Perform in situ hybridization to detect cell-specific localization of mRNAs.